The present invention relates to a method for delivering a gas, and more specifically to a method for delivering a fuel gas such as hydrogen for consumption by a device such as a fuel cell or the like.
A fuel cell is an electrochemical device which reacts hydrogen and oxygen, which is usually supplied from ambient air, to produce electricity and water. The basic process is highly efficient in fuel cells fueled directly by hydrogen and are substantially pollution free.
While fuel cells of the nature described have repeatedly shown advantages and promise for the generation of electrical power for various uses, they have not, however, been widely embraced except for narrow industrial applications in view of several perceived difficulties. For example, one of the most cited shortcomings of fuel cells has been the cost per watt of electrical power generated by same.
One of the factors which contribute significantly to the cost of generating each watt of electrical power from a fuel cell is the cost associated with supplying a suitable source of a fuel gas such as hydrogen for use by the fuel cell. In certain industrial applications such as when fuel cells are used as backup power for emergency applications such as in communications facilities, navigation sites and the like, bottled hydrogen is acceptable as a source of fuel because the fuel cell is normally needed for relatively short periods of time. However, in other applications such as where the fuel cell will become the primary source of power for the particular industrial application, bottled hydrogen is usually considered unacceptable as a source of fuel.
Significant research efforts have been undertaken, as of late, to develop chemical reactors which may be integrated with a fuel cell, and which are operable to take a source of hydrocarbon, such as natural gas, and react it in a fashion such that hydrogen is released for use with the fuel cell. While several chemical reactor or fuel processor designs have recently emerged, as a general matter, they are all somewhat complex in design, costly to manufacture, and have not demonstrated the consistent operational reliability necessary for them to be utilized in wide market applications. Still further, the addition of a chemical reactor to current fuel cell designs has the effect of driving the cost per watt to generate electricity even higher.
Other methods and designs have recently emerged to address this hydrogen distribution problem. For example, several schemes are disclosed and which are shown in references such as U.S. Pat. No. 6,305,442; U.S. Publication No. US2001/0025670; US2002/0029820; and U.S. Pat. No. 6,182,717, for example. A common element found in each of these prior art references is the use of a metal hydride which is used to store hydrogen. Thereafter the device which utilizes hydrogen is coupled with this metal hydride device, and is operable to remove the hydrogen from the metal hydride. While these innovative methods and devices will solve some fuel gas distribution problems, they still contribute significantly to the cost per watt to generate electrical power. Therefore, a method which addresses the perceived shortcomings in the prior art methods, devices, and practices is the subject matter of the present invention.
A first aspect of the present invention relates to a method for delivering a gas and which includes, providing a conduit which supplies natural gas to a geographic location; and mixing a gas to be delivered with natural gas for delivery to the geographic location.
Still another aspect of the present invention relates to a method for delivering a gas to a geographic location and which includes, providing a source of natural gas; providing a conduit coupled in fluid flowing relation relative to the source of natural gas and which delivers a volume of natural gas to the geographic location; providing a source of a gas to be delivered to the geographic location; mixing the source of the gas to be delivered with the natural gas for delivery at the geographic location; providing a first device at the geographic location and which is coupled in fluid flowing relation relative to the conduit and which consumes the natural gas delivered to the geographic location; and providing a second device at the geographic location and which is coupled in fluid flowing relation relative to the conduit, and which consumes the gas which is mixed with the natural gas, and which is delivered to the geographic location.
Yet another aspect of the present invention relates to a method for delivering a gas to a geographic location, and which includes, providing a source of natural gas; providing a natural gas delivery network which is operable to deliver the source of natural gas by way of a conduit to a geographic location; providing a source of a fuel gas to be delivered to the geographic location to the conduit; mixing the source of the fuel gas with the source of natural gas, and wherein the conduit has a volume, and wherein the preponderance of the volume of the conduit comprises natural gas; providing a device at the geographic location and which consumes natural gas during operation, and which is coupled in fluid flowing relation relative to the conduit; and providing an ion exchange membrane fuel cell at the geographic location and which is coupled in fluid flowing relation relative to the conduit and which when supplied with the fuel gas generates electricity.
Still another aspect of the present invention relates to a method of delivering a fuel gas and wherein an accumulator is coupled in fluid flowing relation relative to the conduit, and which stores a volume of the fuel gas delivered by way of the conduit.
Yet a further aspect of the present invention relates to a method of delivering a fuel gas and wherein a chemical reactor which is coupled in fluid flowing relation relative to the conduit, and with the ion exchange membrane fuel cell, and wherein the chemical reactor receives the source of natural gas and chemically converts the source of natural gas into a second source of fuel gas for use by the ion exchange membrane fuel cell.
These and other aspects of the present invention will be discussed in further detail hereinafter.